Fluid dispensing apparatus



V. D. BARKER4 FLUID DISPNS ING' APPARATUS Filed June 18, 1940 fk l Dec.l, 1942.

Patented Dec. 1, 1942 UNITED STATES PATENT OFFICE FLUID DISPENSINGAPPARATUS Virgil D. Barker, Westfield, N. J.

Application June 18, 1940, Serial No. 341,121

10 Claims.

Although not limited to any particular embodiment, my invention may beadvantageously embodied in apparatus for dispensing air at an automobileservice station. At such a station, compressed air is principally usedfor operation of elevators to lift vehicles to permit them to be greasedwith facility; to dispense grease under pressure to the bearings of suchVehicles, and to inate the vehicle tires. It is ordinary practice tohighly compress air, say to 150 pounds per square inch, by a pumpoperated by an electric motor, and to store it in a supply tank fromwhich it may be released through dispensing apparatus which isadjustable to predetermine the pressure to which any air receiver may becharged.

Letters Patent of the United States No. 2,162,474 was granted June 13,1939 to me for Fluid dispensing apparatus, of the class abovecontemplated and operative to dispense compressed air by a succession ofpulsations until the back pressure through the dispensing conduitreaches that to which the controlling means is adjusted. That apparatusincludes two control valves (shown in Fig. VI) each separately springthe dispensing conduit, until the selected pressure, variablypredetermined by manual adjustment of a spring, is attained in the tireor other air receiver. In that patented structure, the two valves areoperated in proper sequence by respective rocker cams, in cooperativerelation with "irespective rocker cam levers, carrying respectiverollers, which are independently spring stressed into cooperativerelation with the rocker cams. It is the object and effect of my presentinvention to simplify the construction, arrangement, and method ofoperation of that patented structure. Both inventions utilize twodiaphragm chambers each containing a pressure sensitive reciprocatorydiaphragm, subjected to stresses in opposite directions by fluidpressure and a spring opposed to such pressure, but, in said patent, thefluid in one of said chambers is continually in communication with theatmosphere through a restricted vent local to that chamber and remotefrom the valve casing in which said two valves are mounted, whereas, inthe presentl invention, the only fluid vent to the atmosphere isunrestricted and in the valve casing containing both of said valves, andwhat is hereinafter termed the second of those valves positivelycontrols the escape of fluid to the atmosphere from the rst diaphragmchamber by alternately opening and closing that unrestricted vent in thevalve casing. Moreover, the present invention includes a restricted ductin the valve casing continually limiting the rate of flow of fluid toone of the diaphragm chambers.

Both of said diaphragms are intermittently subjected to the maximumfluid pressure directly from a supply reservoir or other source, but oneis continually in communication with such source through said restrictedduct, whereas the other diaphragm is continually subjected to fluidpressure from the air service conduit.

Moreover, in said patent both of the valves in the valve casing arearranged to be operated by respective rocker cams which are formed bylevers of the first order, whereas, in the present invention, only oneof the two valves, viz., the one hereinafter designated the first valve,which controls the admission of high pressure air from the sup.. ply toboth the service conduit and the second diaphragm chamber, is arrangedto be operated by a rocker cam, and that cam is formed by a lever of thesecond order. The other valve, hereinafter designated the second valve,is arranged to be directly operated to control the vent of fluidpressure to the atmosphere by a bell crank lever subjected to fluidpressure from the service conduit opposed by the adjustable spring,operated by the fluid, as a lever of the rst order, to close that valve,and operated by the spring, as a lever of the second order, to open thatvalve.

My invention operates in positively controlled cycles to forcesuccessive pulsatory charges oi fluid into a receiver; each charge offluid being automatically terminated at an interval after itsinitiation.

Only a small quantity of the high pressure uid fro-m the source isrequired to furnish sufcient power for operating the apparatus, and itis subsequently exhausted to the atmosphere through said vent in thevalve casing.

My invention comprises the various novel features of construction,arrangement, and method of operation hereinafter more definitelyspecified.

In the drawing,

Fig. I is a rear elevation of a main casing, connected with a conduitleading from the high pressure uid supply reservoir and with a fluiddispensing service conduit, and said casing encloses the two diaphragmchambers and has on the front thereof indicating mechanism, not

Ais turned one-tenth of a revolution.

shown herein, including a plurality of adjustable numbered wheels.

Fig. II is a longitudinal sectional view of the valve casing shown inFig. I and including the restricted vent connecting the two chambers inwhich the valves are respectively mounted, and also including theunrestricted vent to the atmosphere controlled by the second valve.

In said drawing, the main casing I encloses two diaphragm chambers 2 and3, each containing a reciprocatory diaphragm, respectively 4 and 5. Thefluid pressure supply conduit 6, from any suitable source of highlycompressed air, suppliesAv such air to said diaphragm chambers underautomatic valve control, as hereinafter described. The uid pressureservice conduit 8 leads from said chamber 3, and the compressed air isdispensed through it to the receiver. For the purpose of servicing andinating automobile tires, said service conduit 8 may have a fiexibledispensing hosel 8 connected therewith having at the discharge endthereof a suitable connecting fitting or chuck 82, of well known design,for convenient attachment to a tire valve stem 83. Such a chuck embodiesa valve which closes to prevent air from escaping from the hose when notattached to a tire stem, but is automatically opened Aand automaticallyunseats the tire valve when the chuck is properly applied to the tirevalve stem. Rear cover 9 of casing I is partly omitted.

Said diaphragm 5, which is subjected to the iluid pressure in saidservice conduit 8, has op- -eratively connected therewith thereciprocatory plunger The bell crank lever Il, which is fulcrumed on theshaft I2, between a pair of suitable bearings I3 in said casing I, hasits short arm Il' in cooperative relation with said plunger 5' and hasits long arm II connected with the 'right hand end of the spring I5. Theleft hand 'end of said spring I5 carries the nut IE which is in threadedengagement with the adjusting screw I1 cut on the shaft I8 extendingexterior to said casing I and provided with the crank handle I9 by whichit may be adjusted. That is to say, the stress of said spring I5 may beincreased by Iturning said crank I9 clockwise or decreased by turning itcounterclockwise.

I find it convenient to connect with said shaft I8 indicating means formanifesting in pounds the pressure to which .'the receiver is to becharged, Which is predetermined by the manual adjustment of said springI5. Such means includes a gear pinion 2l on said shaft I8 and theintermediate gear 22 which meshes with the indicator mechanism gear 26.

When the crank handle I9 is turned by the operator, the gear 26 turnsthe indicating mechanism which, as Vdisclosed in detail in my Patent No.2,162,474 aforesaid, includes three wheels fsecond numbered wheel, eachof the numbers on which represents tens of pounds, and that secondfwheel is connected, kby tens-transfer gearing,

with the third numbered wheel, each of the numbers on which representshundreds of pounds. That arrangement is such that upon a completerotation of the successive numbered wheels of lower order, the wheel ofthe next higher order Consequently, when the operator turns the crankhandle I9, the three numbered wheels indicate the pounds pressure towhich the apparatus is set by CTI the screw I1 stressing said spring I5to move said bell crank lever II. For instance, in the position shown,the screw I1 has been manually adjusted to insure dispensation ofcompressed air through the service conduit 8 until an automobile tire orother receiver is charged to a pressure of thirty-five pounds per squareinch.

Said supply conduit 6 is connected with the valve casing 30 incommunication with the valve chamber 3l therein, which is connected bythe restricted air duct 32 with the valve chamber 33 having the passage34 leading to the unrestricted vent 35 which opens through said casing30 to the atmosphere.

Said valve chamber 33 is continually in communication with the fluidconduit 36 so that, when the passage 34 is closed, as shown in Fig. IIand as hereinafter described, the high pressure air from the supplyconduit 6 passes through the restricted air duct 32 and said air conduit33 into lthe chamber 2 beneath the diaphragm 4, stressing the latterupward. The passage 31 leads from the valve chamber 3l tothe air conduit38 which extends tothe diaphragm chamber 3 beneath the diaphragml 5 andto the service conduit 8 through the T-tting 38. Therefore, whensaid'passage 31 is open, the high pressure air is also supplied to thechamber 3 tending to uplift the diaphragm 5.

The first valve 4B, which is mounted to recipstressed toward its closedposition shown in Fig.

stationary stud 49 fixed Ain the casing I.

II by its spring 4I tending to close said passage 31 leading to the airconduit 38. However, said valve 40 is arranged to be opened by its stem40 which extends through the stufng box 42 `on said valve casing 30 andis pivotally con- 'nected with the left hand end of the link 43, ofwhich the right hand end is pivotally connected with the rocker cam 44which is a lever of the second order fulcrumed on the stud 45 fixed insaid casing I. The upper end of said rocker cam y44 has the right handincline 44 engaged by the roller 46 carried by the cam roller lever 41and continually stressed into cooperative engagement with the rocker cam44 by the spring 48 connecting the right hand end of said lever 41 withthe The movement of said rocker cam 44 is limited by the stop studs 5I!and 5I xed in said casing I and,`

in the position shown, the roller 46 engaging the 'rocker cam 44 hasthrust the valve 40 open so that the high pressure air is passing fromthc supply conduit 5 into the diaphragm chamber 3 and the fluid serviceconduit 8, but the diaphragm 5 has not begun to move from its lowermostposition shown in Fig. I in which it is held -by the short arm II of thebell crank lever II under stress of the adjustable spring I5.

-said lever I I by the spring I5.

'Ihe construction and arrangement above described are such that the highpressure air flowing into the diaphragm chamber 3 and service conduit 8lifts the diaphragm 5 and turns the lever II clockwise against thestress of its spring vI5 to close the passage 34 in the valve casing 30by the valve 51, as shown in Fig. II, under stress of its spring 51". l

aeoasm 3 However, saidl valve is arranged to be opened by its rod 51',the right hand end of which is pivotally connected to the left hand endof. the link 58, of which the right hand end is pivotally connected tothe long armv II of said lever II. Fig. I shows the parts in the.position in which the valve 51 is open to exhaust the air from thediaphragm chamber 2 beneath the diaphragm 4.

Said diaphragm 4, which is normally subjected to the high pressure fluidfrom the supply conduit 6 when the valve 51 is in the position shown inFig. II, is relieved of that pressure when the valve 51 is open in theposition ofthe parts shown in Fig. I, by the exhaust of the compressedair from the chamber 2 through the air conduit 36, casing 30, and theunrestrictedvent 35 leadn ing to the atmosphere, so that the diaphragm 4then sinks to the position shown in Fig. I. Said diaphragm 4 hasoperatively connected therewith the reciprocatory plunger 4. lever Sil,which is fulcrumed on the shaft EI, between a pair of suitable'bearings62 in said casing I, has its short arm 60' in cooperative relation withsaid plunger 4', and has its long arm Si!" connected with the left handend of the spring i E4. The right hand end of said spring (i4 isanchored on said stud 55. Said cam roller lever 41 is fulcrumed on thepin 65 fixed in the long arm 6B of said lever 60; so that the stress ofsaid spring 64 has shifted the long arm 63" i against the stop lug BISconveniently formed on the upper portion of the valve casing 3o, asshown in Fig. I, and with the effect of placing the cam roller 46 inengagement with the right hand incline 44' of said cam 44 and thrusting'Y the valve 40 to open position in which the high pressure air isadmitted through the passage 31 Vto the fluid conduit 38 to lift thediaphragm 5 and charge the service conduit 8 with air at the highpressure from the source.v However, as f above noted, Fig. I shows theposition of the parts with both valves open and immediately be fore thediaphragm 5 has been uplifted to turn the lever II clockwise at theinitiation of a pulsation of pressure caused by reduction of pressure inthe conduit 8 below that for which the spring I5 has been adjusted. Thatis also the position of the parts shown in Fig. I when the supplyconduit Ii and service conduit 8 are disconnected respectively from thesource of supply and the receiver to be charged.

When the supply conduit is connected with a source of highly compressedair and the service conduit 8 closed at its discharge end by the chuckvalve, or any other means, both the diaphragm chambers 2 and 3 arecharged with the high pressure air, uplifting the diaphragms 4 and 5 andturning the bell crank levers II and 60 to the limit of their movementrespectively clockwise and counterclockwise. Such movement of the leverII is limited by contact of its arm II" with the inner face of the righthand side wall of the casing I. Such movement of the lever 50 is limitedby the contact of the stop screw 61 which is axially adjustable in thearm Sii" of that lever and may be set in adjusted position by the nut 68thereon. Said screw S1 encounters the inner face of the left hand wallof said casing I. Such movement of the vlever 6D causes the roller 46 topass over the crest of Cil The bell crank f,

4B from the casing 30 and permitting the valve 40 to be closed by itsspring 4I. Such clockwise movement of the lever II causes the link 58 towithdraw the rod 51 of the valve 51 from the casing 3i.) and permitsthat valve to be closed by its spring 51". It may be observed withreference to Fig. II that the valve rods 4Q and 51' are each made in twosections in order to fit them into the valve casing 39, in view of theenlargements at both ends of said rods.

Both the supply conduit E and the service conduit 8 being charged withhighly-compressed air, and the stress of the spring I5 being adjusted tothe pressure desired in a receiver, for instance a vehicle tireconnection of the chuck valve at the discharge end of the serviceconduit with the tire valve stem permits the high pressure air in theconduit I3 to escape into the tire until the pressure in the tire and inthe service conduit is equalized, by decrement of the pressure in theconduit 8 and increment of the pressure in the tire. The decrement ofpressure in the diaphragm chamber 3 beneath the diaphragm 5 permits thespring I5 to turn lever II counterclockwise with the effect of thrustingopen the valve 51 by the link 58 and the rod 51 of that valve, thuspermitting the escape of the high pressure air from the diaphragmchamber 2 beneath the diaphragm 4, through the air conduit 355, casing3D, and the unrestricted vent opening 35 in the valve casing 3S. Suchventing of the diaphragm chamber 2 permits the spring 64 to turn thelever 53 clockwise to the position shown in Fig. I, with the effect offorcing the roller 46 over the crest of the cam 44 to the right handside thereof and permitting the spring 4S to rock the cam 44counterclockwise to the position shown in Fig. I and thereby open thevalve 4t to admit a pulsatory charge of highly compressed air todiaphragm chamber 3 and the service conduit 8. Such pulsatory chargesare automatically effected in succession until the pressure in the tireor other receiver equals the pressure to which the spring i5 has beenadjustably set. Thereupon, disconnection of the service conduit 8 fromthe tire permits the chuck valve to close and trap the highly compressedair from the source in the diaphragm chambers 2 and 3 and serviceconduit 8, ready for the initiation of another dispensing operation bypermitting the highly compressed air to escape from the discharge end ofthe service conduit 8, as above described.

However, I do not desire to limit myself to the precise details ofconstruction, arrangement, or method of operation herein set forth, asit is obvious that various modifications may be made therein Withoutdeparting from the essential features of my invention, as deiined in theappended claims.

I claim:

l. In fiuid dispensing apparatus, the combination with a casingenclosing two diaphragm chambers, each containing pressure sensitivemeans including a reciprocatory diaphragm; of a uid pressure supplyconduit through which fluid is supplied to said chambers; a valve casingincluding a constantly open restricted fluid duct connecting the supplyconduit to the first chamber and a controlled vent to the atmosphere; afluid pressure service conduit leading from the second chamber;respective springs opposed to the fluid pressure on said diaphragm;means for adjustabiy varying the pressure of the spring opposed to thediaphragm in the second chamber; a first valve in said valve casing,controlling communication between the fluid pressure supply conduit andsaid second chamber; a second valve in said valve casing, controllingcommunication from said first chamber, through said controlled vent, tothe atmosphere; means operatively connecting said second valve with thediaphragm in said second chamber and the spring opposed to thatdiaphragm; whereby said second valve is arranged to be closed by fluidpressure in the second chamber, and opened by the stress of the springopposed to the diaphragm in said second chamber to vent the fluidpressure from the first chamber to the atmosphere; whereby uponreduction of iiuid pressure in the second chamber below that for whichthe spring opposed thereto is adjusted, that spring opens said secondvalve, thereby exhausts the fluid pressure from the diaphragm in thefirst chamber and causes the first valve to be automatically opened,admitting the full yfluid pressure from the source both to said serviceconduit and to the diaphragm in said second chamber, thereby iirstcausing said second valve to be closed, and thereafter said first valveto be closed when the pressure in the first chamber, connected by theconstantly open restricted duct to the supply conduit, overcomes thespring opposed to said rst chamber diaphragm, until the fluid pressurein said second chamber is again reduced below that for which the springopposed thereto is adjusted; whereupon the cycle of operation isrepeated and said valves are automatically operated in accordance withfluctuations in the iiuid pressure on both diaphragms and fiuid isdispensed, in successive pulsations, from said supply conduit throughsaid service conduit, until the pressure in the receiver is equal to theeffective pressure of the adjusted spring; wherein the valves haverespective springs continually stressing them toward their closedposition, and means operatively connecting the first valve with thediaphragm in the first chamber and the spring opposed to that diaphragmincluding a bell crank lever, having a short arm in cooperative relationwith that diaphragm and a long arm in cooperative relation with thelatter spring, a rocker cam, a cam lever carrying a roller and pivotedat one end to said long arm, a spring continually stressing the camlever with its roller in cooperative relation with the cam,

and a valve push rod in operating relation with said rocker cam.

2. In fluid dispensing apparatus, the combination with a casingenclosing two diaphragm chambers, each containing pressure sensitivemeans including a reciprocatory diaphragm; of a uid pressure supplyconduit through which fluid is supplied to said chambers; a valve casingincluding a constantly open restricted fluid duct connecting the supplyconduit to the first chamber and a controlled vent to the atmosphere; aiiuid pressure service conduit leading from the second chamber;respective springs opposed to the fluid pressure on said diaphragm;means for adjustably varying the pressure of the spring opposed to thediaphragm in the second chamber; a first valve in said valve casing,controlling communication between the fluid pressure supply conduit andsaid second chamber; a second valve in said Valve casing, controllingcommunication from said first chamber, through said controlled vent, tothe atmosphere; means operatively connecting said second valve with thediaphragm in said second chamber and the spring opposed to thatdiaphragm; whereby said second valve is` arranged toV be closed byfluidpressure in the second chamber, and opened bythe stress of thespring opposed to the diaphragm in said second chamber to vent the uidpressure from the first chamber to the atmosphere; whereby uponreduction of fluid pressure in the second chamber below that for whichthe spring opposed thereto is adjusted, that spring opens said secondvalve, thereby exhausts the fluid pressure from the diaphragm in thefirst chamber and causes the first valve to be automatically opened,admitting the full fluid pressure from the source both to said serviceconduit and to the diaphragm in said second chamber, thereby rst causingsaid second valve to be closed, and thereafter said first valve to beclosed when the pressure in the first chamber, connected by theconstantly open restricted duct to the supply conduit, overcomes thespring opposed to said first chamber diaphragm, until the iiud pressurein said second chamber is again reduced below that for which the springopposed thereto is adjusted; whereupon the cycle of operation isrepeated and said valves are automatically operated in accordance withfluctuations in the iiuid pressure on both diaphragms and fluid isdispensed, in successive pulsations, from said supply conduit throughsaid service conduit, until the pressure in the receiver is equal to theeffective pressure of the adjusted spring; wherein the valves haverespective springs continually stressing them toward their closedposition, the means operatively connecting the second valve with thediaphragm in the second chamber and the spring opposed to that diaphragmincludes a bell crank lever, having a short arm in cooperative relationwith that diaphragm and a long arm in cooperative relation with thelatter spring, and a valve push rod operatively connected to said longarm.

3. In iiuid dispensing apparatus, the combination with a casingenclosing two diaphragm chambers, each containing pressure sensitivemeans including a reciprocatory diaphragm; of a fiuid pressure supplyconduit through which fluid is supplied to said chambers; a valve casingincluding a constantly open restricted fluid duct connecting the supplyconduit to the first chamber and a controlled vent to the atmosphere; afluid pressure service conduit leading from the second chamber;respective springs opposed to the fluid pressure on said diaphragm;means for adjustably'varying the pressure of the spring opposed to thediaphragm in the second chamber; a first valve in said valve casing,controlling communication between the iiuid pressure supply conduit andsaid second chamber; a second valve in said valve casing, controllingcommunication from said first chamber, through said controlled vent, tothe atmosphere; means operatively connecting said second valve with thediaphragm in said second chamberandth'e spring opposed to thatydiaphragm; whereby said second valve is arranged to be closed by iiuidpressure in the second chamber, and opened `by the stress of the springopposed to the diaphragm in said second chamber to vent the iiuidpressure from the first chamber to the atmosphere; whereby uponreduction of fluid pressure in the second chamber below that for Whichthe spring opposed thereto is adjusted, that spring opens said secondvalve, thereby exhausts the fluid pressure from the diaphragm in thefirst chamber and causes the first valve to be automatically opened,admitting the full fluid pressure from the source both to said serviceconduit and to the diaphragm in said second chamber, thereby firstcausing said second -valve to be closed, and thereafter said rst valveto be closed when the pressure in the rst chamber, connected by theconstantly open restricted duct to the supply conduit, overcomes thespring opposed to said rst chamber diaphragm, until the uid lpressure insaid second chamber is again reduced below that forwhich the springopposed thereto is adjusted; whereupon the cycle of operation isrepeated and said valves are automatically operated in accordance withfluctuations in the uidvpressure on both diaphragms and fluid isdispensed, in successive pulsations, from said supply conduit throughsaid service conduit, until the pressure in the receiver is equal to theeiect-ive pressure of the adjusted spring; wherein the means operativelyconnecting the first valve with the diaphragm in the first chainber andthe spring opposed to that diaphragm includes a bell crank lever, havinga short arm in cooperative relation with that diaphragm and4 a long armin cooperative relation with that spring, a rocker cam, a cam rollerlever carrying a roller and pivoted at one end to said long arm,

a spring continually stressing the cam roller lever with its roller incooperative relation with the cam, anda valve push rod in operatingrelation with said rocker cam; the valves have respective springscontinually stressing them toward their closed position, and the meansoperatively connecting the second valve with the diaphragm in the secondchamber and the adjustable spring opposed to that diaphragm includes abell crank lever, having a short arm in cooperative relation with thatdiaphragm and a long arm in cooperative relation with the latter spring,and a valve push rod operatively connected to said long arm.

4. In fluid dispensing apparatus7 the combination with a casingenclosing two diaphragm chambers, each containing pressure sensitive Ymeans including a reciprocatory diaphragm; of a fluid pressure supplyconduit through which fluid is supplied to said chambers; a valve casingincluding a constantly open restricted fluid duct connecting thepressure supply conduit to a conduit leading to the first chamber and acontrolled fluid vent to the atmosphere; a uid pressure service conduitleading from the second chamber; respective springs opposed to theii'uid pressure on said diaphragms; means for adjustably varying thepressure of the spring opposed to the diaphragm in the second chamber; arst valve in said valve casing, controlling communication between theiiuid pressure supply conduit and said second chamber; a second valve insaid valve z casing controlling communication from said rst chamber,through said casing vent, to the atmosphere; and means operativelyconnecting said first valve with the diaphragm in said first chamber andthe spring opposed to that diaphragm, including a lever; whereby saidfirst valve is arranged to be opened by the stress oi the spring opposedto said first diaphragm and closed by fluid pressure on said firstdiaphragm; means operatively connecting said second valve with thediaphragm in said second chamber, including a lever; whereby said secondvalve is arranged to be closed by uid pressure in said second chamber,and opened by the stress of the spring opposed to the diaphragm in saidsecond chamoer to vent the uid pressure from the first chamber, throughsaid valve casing, to the atmosphere.

l5. In fluid dispensing apparatus, the combination with a casingenclosing two diaphragm Vcontrolled -uid vent to the atmosphere; a fluidpressure service conduit leading from the second chamber; respectivesprings opposed to the uid Y 4p ':essure on said diaphragms; means foradjustably varying the pressure of the spring opposed to the diaphragmin the second chamber; a first valve in said valve casing, controllingcommunication between the fluid pressure supply conduit and said secondchamber; a second valve in said valve casing controlling communicationfrom said first chamber, through said casing vent, to the atmosphere;means operatively connecting said first valve with the diaphragm in saidfirst chamber and the spring opposed to that diaphragm, including alever of the rst order; whereby said first valve is arranged to beopened by the stress of the spring opposed to said first diaphragm andclosed by fluid pressure on said rst diaphragm; means operativelyconnecting said second valve with the diaphragm in said second chamber,including a lever of the rst order; whereby said second valve isarranged to be closed by fluid pressure in said second chamber, andopened by the stress of the spring opposed to the diaphragm in saidsecond chamber to vent the fluid pressure from the riirst chamber,through said valve casing, to the atmosphere.

6. In fluid dispensing apparatus, the ycombination with a casingenclosing two diaphragm chambers, each containing pressure sensitivemeans including a reciprocatory diaphragm; of a fluid pressure supplyconduit through which fluid is supplied to said chambers; a valve casingincluding a constantly open restricted fluid duct connecting thepressure supply conduit to a conduit leading to the first chamber and acontrolled uid vent to the atmosphere; a fluid pressure service conduitleading from the second chamber; respective springs opposed to the fluidpressure on said diaphragms; means for adjustably varying the pressureof the spring opposed to the diaphragm in the second chamber; a firstvalve in said vaive casing, controlling communication between the fluidpressure supply conduit and said second chamber; a second valve in saidvalve casing controlling communication from said rst chamber, throughsaid casing vent, to the atmosphere; means operatively connecting saidfirst valve with the diaphragm in said first chamber and the springopposed to that diaphragm, including a bell crank lever; whereby saidfirst valve is arranged to be opened by the stress of the spring opposedto said first diaphragm and closed by fluid pressure on said firstdiaphragm; means operatively connecting said second valve with thediaphragm in said second chamber, including a bell crank lever; wherebysaid second valve is arranged to be closed by fluid pressure in saidsecond chamber, and opened by the stress of the spring opposed to thediaphragm in said second chamber to vent the fluid pressure from thefirst chamber, through said valve casing, to the atmosphere.

7. In fluid dispensing apparatus, the combination with a casingenclosing two diaphragm chambers, each containing pressure sensitivemeans including a reciprocatory diaphragm; of ya fluid pressure supplyconduit through which uid is supplied to said chambers; a valve casingincluding a constantly open restricted uid duct connecting said pressuresupplyr conduit to a conduit leading to the rst chamber and a controlledfluid vent to the atmosphere; a uid pressure service conduit leadingfrom the second chamber; respective springs opposed to the fluidpressure on said diaphragms; means for adjustably varying the pressureof the spring opposed to the diaphragm in the second chamber; a rstvalve in said valve casing, controlling communication between the fluidpressure supply conduit and said second chamber; a second valve in saidvalve casing controlling communication from said rst chamber, throughsaid casing vent, to the atmosphere; means operatively connecting saidrst valve with the diaphragm in said rst chamber and the spring opposedto that diaphragm, including a lever of the rst order, a lever of thesecond order forming a rocker cam, a cam lever carrying a roller, and aspring stressing said roller toward said cam, whereby said first valveis arranged to be opened by the stress of the spring opposed to said rstdiaphragm and closed by uid pressure on said :rst diaphragm;

means operatively connecting said second valve with the diaphragm insaid second chamber in` cluding al lever; whereby said second valve isarranged to be closed by uid pressure in said second chamber, and openedby the stress of the spring opposed to the diaphragm in said secondchamber to vent the fluid pressure from the rst chamber, through saidvalve casing, to the atmosphere.

8. A structure as in claim 4, wherein the lever operatively connected tothe spring opposed to the diaphragm in the flrst diaphragm chamber,carries means for adjustably varying the extent of its movement by thatdiaphragm,

9. A structure as in claim 4, wherein the lever operatively connected tothe spring opposed to vthe diaphragm in the second chamber, carriesmeans for adjustably varying the extent of its movement by that spring.

10. A structure a-s in claim 4, wherein each of the two leversrespectively connected to the two springs opposed to the -two diaphragmscarries screw means for adjustably varying the extent of its movement.

VIRGlL D. BARKER.

